Python for Secret Agents

Solving problems – recovering a lost password

We'll apply many of our techniques to writing a program to help us poke around inside a locked ZIP file. It's important to note that any competent encryption scheme doesn't encrypt a password. Passwords are, at worst, reduced to a hash value. When someone enters a password, the hash values are compared. The original password remains essentially unrecoverable except by guessing.

We'll look at a kind of brute-force password recovery scheme. It will simply try all of the words in a dictionary. More elaborate guessing schemes will use dictionary words and punctuation to form longer and longer candidate passwords. Even more elaborate guessing will include leet speak replacements of characters. For example, ...